Physics

Investigating the "Spinning Coin" (Euler Disk) Problem

Submitted by Rich on Thu, 06/15/2017 - 21:29

Most everyone has spun a coin on its edge on a table top, and many find the result quite fascinating.  The coin gradually begins to fall on its side while spinning, makes a whirring sound with increasing frequency the longer it spins, and then abruptly stops.  The Swiss physicist, Leonhard Euler, studied this back in the 1700's.  An educational toy, referred to as Euler's disk can now be purchased on-line and in hobby shops specializing in science.  Such disks have been carefully engineered to spin for a much longer time than a coin.

 

Measure the Angle of an Incline Plane

Submitted by PocketLab on Fri, 06/02/2017 - 19:34

Exploration

An accelerometer is a device that will measure acceleration forces. These forces may be static, like the constant force of gravity pulling us towards the Earth’s surface, or the force may be dynamic, like an object moving or vibrating. This lab will show how to use to accelerometer to measure the static angle of a ramp as it rotates between 0° and 90°.

Objective

Angular Velocity of Rolling Object at Different Inclines

Submitted by PocketLab on Fri, 06/02/2017 - 19:29

Exploration 

The moment of inertia (MOI) is the rotational inertia of an object as it rotates about a specific axis. Moment of inertia determines the torque required for a specific angular rotation about an axis. The moment of inertia depends upon the distribution of mass of the rotating object in relation to the axis the object is rotating about.

Objective

Rotating Book

Submitted by PocketLab on Fri, 06/02/2017 - 18:59

Exploration

The moment of inertia (MOI) is the rotational inertia of an object as it rotates about a specific axis. Moment of inertia determines the torque required for a specific angular rotation about an axis. The moment of inertia depends upon the distribution of mass of the rotating object in relation to the axis the object is rotating about. Explore whether the stability of a book’s rotation is dependent upon the moment of inertia and therefore whether it changes based on the axis the book is rotating about.

Objective

Friction on a Turntable

Submitted by PocketLab on Fri, 06/02/2017 - 18:56

Exploration

An inertial force arises from the rotation of the object and the object mass (sometimes called the centrifugal force, not to be confused with centripetal force). If the inertial force is greater than the force of friction, the object will slide off of the rotating turntable (following Newton’s First Law of Motion). The parameters that cause the inertial force to be greater than the force of friction depend on many variables.

Objective

Arms of a Spinning Figure Skater

Submitted by PocketLab on Fri, 06/02/2017 - 18:52

Exploration

When a figure skater spins he/she uses the positioning of his/her arms to control the speed of the spin/ angular velocity. The angular momentum of the skater is always conserved, no matter the positioning of the arms, and can be represented by the equation L = Iw, where L is angular momentum, I is moment of inertia and w is angular velocity. The moment of inertia is an object’s resistance to change in angular velocity and is related to the distribution of the object’s mass.

Objective

Understanding Centripetal Force

Submitted by PocketLab on Fri, 06/02/2017 - 18:46

Exploration

An object experiencing a constant net force will experience a constant acceleration. Acceleration is defined as either a change in speed or a change in direction. When an object moves along a curved path it may maintain its speed, however it will be constantly changing its direction of movement. This type of acceleration along a curved path is called centripetal acceleration and is the result of a centripetal force, a force that is directed inward, toward the center of the curvature of the path. Examine the figure below.

Soup Can Race

Submitted by PocketLab on Fri, 06/02/2017 - 18:39

Exploration

When two cans of different geometries are released from rest at the same time at the top of an inclined plane the results of the race may not be what you predict. The moment of inertia of each soup can will affect whether it reaches the end of the inclined plane first.

Objective

In this experiment, students will:
1. Determine the order in which each can will reach the bottom of the ramp first and explain why in terms of the energy in the system and the moment of inertia in each can.

Intro to Angular Velocity

Submitted by PocketLab on Fri, 06/02/2017 - 18:24

Exploration

We have previously learned that velocity is an object’s rate of change in displacement. Velocity is often measured as meters/second. Angular velocity however, measures the rate of change in the displacement of an object as it moves around a central point.

Pressure and Volume with a Syringe

Submitted by PocketLab on Fri, 06/02/2017 - 18:11

Exploration 

Explore air pressure and how it works. In a sealed syringe, as the plunger moves back and forth, the volume of air in the syringe changes. With a large enough syringe, a PocketLab can be placed inside to measure the change in pressure as the the volume changes.

Objective

In this experiment, students will:
1. Determine the relationship between air pressure and volume using a syringe.
2. Explore what is happening to the air molecules when there is a greater or less air pressure.